It seems that Bundy is experiencing what is known as vestibular signs, meaning that he is having issues with spacial orientation an balance. Vestibular signs in dogs often manifests as walking in circles, often tilting their head in the same direction they tend to circle. Often, you will also see a horizontal jerking of the eyes called nystagmus...but mind you, not all cases of vestibular disease manifest with all the signs at once, but may exhibit only one or a few of the aforementioned signs. We call this condition in people, vertigo.
The vestibular system is made up of the fluid apparati in both inner ears, as well as the nerves that course from those regions to transmit the sensory information. The nerves specifically are called the vestibular nerves, and they end in a nerve bundle in the brain stem called the vestibular center.
The most common reason for vestibular disease in aging dogs is inflammation of the vestibular nerve, or inflammation of the vestibular center in the brain stem. The particular vestibular nerve and/or center involved is most typically on he same side that the dog will circle toward and/or tilt his head.
We do not really know what sets off vestibular inflammation and subsequent "vestibular syndrome" but the good news is that it typically resolves spontaneously within hours to as long as 14 days. While we are waiting for the issue to resolve, we will typically treat symptomatically with the anti-vertigo medication, meclizine (more on this below).
Another cause for vestibular signs in dogs is ear infections. Therefore, the first thing I would like you to do is check the ears for signs of infection: pain, foul smell, redness, discharge...anything like this, then I would get Bundy to a vet immediately.
If you do not find any signs of ear infection, then you can try treating with meclizine to see if you can get BUndy some relief while you are waiting for a presumed vestibular syndrome to resolve, which it should.
Meclizine can be found over the counter as Bonine. It comes in 25 mg tablets, of which you would give Bundy 1/2 tablet once daily by mouth. Bonine is used in people for relief from vertigo, but it is also commonly used to prevent motion sickness (for boats or airline travel).
Bear in mind that bonine will only provide symptomatic relief from the unstable world bundy may be experiencing right now, but it will not speed up his recovery...that will proceed on its own within hours to 14 days of the onset of signs.
If within a day or two, the meclizine is not giving Bundy enough relief to eat, drink, urinate, defecate outside, then he should be admitted to a veterinary hospital for supportive care, as these circumstances could lead to dehydration and further complications.